Active web spreading and stabilization shower

ABSTRACT

Described herein are methods and systems for reducing, preventing, or eliminating wrinkles in a paper sheet during papermaking. The systems may include a dryer configured to dry a continuous paper sheet having a travel direction. The system may also include at least one roll configured to receive the dried continuous paper sheet. The systems may also include an air spreader located downstream of the dryer and upstream of the at least one roll. The at least one roll may include one or more calendering rolls. The air spreader may include a plurality of nozzles configured to expel a gas toward the dried sheet. The nozzles may be oriented in a direction at least partially opposed to the travel direction of the dried sheet.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based on U.S. Provisional Patent Application No.62/090,684, filed Dec. 11, 2014, which is incorporated herein byreference in its entirety.

BACKGROUND

The present disclosure relates to paper manufacturing and processing.The present disclosure also relates to methods and systems for reducing,eliminating, or preventing folding or wrinkling prior to, or as part of,winding or calendering processes.

During paper manufacturing and processing, a paper web or sheet can passthrough one or more calendering rolls to control the thickness, bulk,and/or surface properties of the web. In some instances, calendering caninvolve passing a continuous web between a pair of continuously-turningrollers having a pattern or texture that is imparted to the web as theweb passes between the calendering rollers. In other instances,calendering can involve passing a continuous web between a pair ofcontinuously-turning rollers to impart smoothness or uniformity to thesurface of the web as the web passes between the calendering rollers.

The web can also be wound onto a large roll or reel one or more timesduring the process. The winding process involves continuously andrepeatedly turning a large roll about a central shaft, drawing the papersheet onto the roll as the sheet leaves another component of the papermachine. For example, the winding process may occur as the web exits adrying section of the paper machine or as the web exits the calenderingrollers. The web may also be rewound following a first winding sectionin one or more subsequent roll-to-roll winding sections.

Paper manufacturing and processing typically involves moving the paperproduct at very high speeds. Because of these high speeds, defects mayoccur in the web. For example, the paper product may experiencewrinkles, folds, curling, edge flutter, and the like. Certain paperprocessing operations, such as calendering and winding, increase thelikelihood of these defects. For example, as the web passes from a dryerto the calendering rollers, folds and wrinkles form as the web istransported to the calendering rollers. These folds and wrinkles can becompressed by the calendering rollers, creating folds, wrinkles, orother defects in the web and also defects in the calendered patternimparted by the rollers. These folds, wrinkles, and pattern defects aretypes of “visual defects” that are seen in the final paper web.

Various methods have been employed in order to control a paper web toavoid such defects. For example, mechanical spreading has been used,which requires a web to be dragged over bowed elements. However, suchdragging action typically has negative effects on sheet properties. Suchprior methods are not ideal, typically having negative effects on sheetproperties, and are not as effective at higher speeds. They also do notsufficiently reduce folding and wrinkling in the calendering and windingprocesses, resulting in visual defects in the final product.

Accordingly, a need exists for an improved method of reducing,preventing, or eliminating defects in the papermaking process that doesnot suffer from the problems discussed above. The present disclosureprovides advantages over prior mechanical spreading means by applyingair to directly spread the web via an air spreader, such as withoutdragging the web over various elements. The application of a foil on theopposite side of the web may also provide additional advantages tosupport the web as the gas is expelled against it. The air spreaderdescribed herein also provides certain advantages to decrease or reducewrinkles and folds in the web as it proceeds to, for example,calendering rollers, embossing rollers, or winding rollers, whichprevents visual defects, such as wrinkles, folds, or pattern defects inthe final web.

SUMMARY OF THE DISCLOSURE

In accordance with certain aspects and embodiments of the presentdisclosure, various methods, devices, and systems are described forreducing, preventing, or eliminating defects in a paper web or sheet,such as visual defects including wrinkles or folds, during or prior tocalendering or winding. The terms “web” and “sheet” are usedinterchangeably herein, unless otherwise indicated.

According to an aspect of this disclosure, a system for reducingwrinkles in a paper sheet during papermaking may include a dryerconfigured to dry a continuous paper sheet. The system may also includeat least one roll configured to receive the dried continuous papersheet. The system may also include an air spreader located downstream ofthe dryer and upstream of the roll. The air spreader may include aplurality of nozzles configured to expel a gas toward the dried sheet.The nozzles may be oriented in a direction at least partially opposed tothe travel direction of the dried sheet.

According to one aspect, the dryer may be a Yankee dryer. According toanother aspect, the dryer may be a through-air-dryer. According toanother aspect, the at least one roll may include a calendering roll ora pair of calendering rolls. According to another aspect, the at leastone roll may be a winding roll or rewinding roll. According to anotheraspect, the at least one roll may include a calendering roll followed byone or more winding rolls.

According to a further aspect, the system may include a positioningcomponent configured to change the position of the air spreader. Thepositioning component may be configured to move the position of the airspreader between a resting position and a working position. The workingposition may be closer to the sheet than the resting position. Thesystem may also include a control unit configured to pressurize the airspreader when the air spreader is in the working position, and todepressurize the air spreader when the air spreader is in the restingposition.

According to still a further aspect, the air spreader may be configuredto expel the gas toward the sheet at a direction and a velocitysufficient to reduce wrinkles in the sheet. The air spreader may beconfigured to expel the gas toward the sheet at a direction and avelocity sufficient to increase tension within the sheet.

According to another aspect, each nozzle in the plurality of nozzles maybe configured to expel a cone-shaped stream of gas toward the sheet.

According to yet another aspect, each nozzle in the plurality of nozzlesmay include a metal tube extending from a base portion of the airspreader.

According to a further aspect, the system may include a dust collectorconfigured to collect dust removed from the dried sheet by the airspreader.

The method may also include providing a foil along a portion of a firstside of the dried paper web. The method may include expelling a gastoward a second side of the dried paper web, opposite the first side,via an air spreader. The air spreader may include a plurality of nozzlesoriented in a direction at least partially opposed to the traveldirection of the dried paper web. The method may include subsequentlycontacting the dried paper web with at least one roll.

According to one aspect, the at least one roll may be a calenderingroll. The calendering roll may be downstream of the air spreader.

According to another aspect, the at least one roll may be a windingroll. The winding may be downstream of the air spreader. The windingroll may also be downstream of a calendering roll.

According to a further aspect, the method may include positioning theair spreader using a moveable positioning component. The method mayinclude rotating the air spreader between a resting position and aworking position. The working position may be closer to the dried paperweb than the resting position.

According to another aspect, expelling gas toward the dried paper webmay include expelling the gas at a direction and velocity sufficient toreduce wrinkles in the dried paper web. Expelling the gas toward thedried paper web may include expelling the gas at a direction andvelocity sufficient to increase tension within the dried paper web.

According to still another aspect, each nozzle in the plurality ofnozzles may include a metal tube extending from a base portion of theair spreader. Each nozzle in the plurality of nozzles may expel acone-shaped stream of gas.

According to yet a further aspect, the method may include pressurizingthe air spreader when the air spreader is in the working position, anddepressurizing the air spreader when the air spreader is in the restingposition. The system may further include a control unit configured topressurize the air spreader when the air spreader is in the workingposition, and to depressurize the air spreader when the air spreader isin the resting position.

According to another aspect, a system for stabilizing a web may includea web that has a travel direction. The web may have a first side and asecond side. The system may include a foil disposed along a portion ofthe first side of the web. The system may include an air spreaderlocated in proximity to the second side of the web. The air spreader mayinclude a plurality of nozzles configured to expel a gas toward thesecond side of the web in a direction at least partially opposed to thetravel direction.

According to another aspect, the system may include a dryer locatedupstream of the air spreader and configured to dry of the web. The dryermay be a Yankee dryer.

According to a further aspect, the system may include at least one rolldownstream of the air spreader. The at least one roll may include atleast one calendering roll. The at least one roll may include at leastone winding roll.

According to another aspect, the air spreader may be attached to apositioning component configured to change a position of the airspreader. The positioning component may be rotatable such that the airspreader can be moved between a resting position and a working position.The working position may be closer to the web than the resting position.

According to another aspect, the air spreader may be configured to expelthe gas toward the second side of the web at a direction and a velocitysufficient to reduce wrinkles from the web.

According to a further aspect, the air spreader may be configured toexpel the gas toward the second side of the web at a direction and avelocity sufficient to increase tension within the web.

According to yet another aspect, each nozzle in the plurality of nozzlesmay include a metal tube extending from a base portion of the airspreader. Each nozzle in the plurality of nozzles may be configured toexpel a cone-shaped stream of gas.

Additional advantages of the described methods, devices, and systemswill be set forth in part in the description which follows, and in partwill be obvious from the description, or may be learned by practice ofthe disclosure. The advantages of the disclosure will be realized andattained by means of the elements and combinations particularly pointedout in the appended claims.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory onlyand are not restrictive of the invention, as claimed.

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate several embodiments and togetherwith the description, serve to explain the principles of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a side view of an exemplary papermaking system.

FIG. 2A shows cross-section of a portion of an exemplary air spreadertaken about plane A-A of FIG. 1.

FIG. 2B shows a portion of an exemplary air spreader taken about planeB-B of FIG. 1.

FIG. 3A shows a portion of an exemplary papermaking system and exemplarymovement of an air spreader.

FIG. 3B shows a portion of an exemplary papermaking system and exemplarymovement of an air spreader.

FIG. 3C shows a portion of an exemplary papermaking system and exemplarymovement of an air spreader.

FIGS. 4A-4H show exemplary nozzles that may be used with an exemplaryair spreader.

DESCRIPTION

Reference will now be made in detail to certain exemplary embodiments,examples of which are illustrated in the accompanying drawings. Wherepossible, the same reference numbers will be used throughout thedrawings to refer to the same or like items.

FIG. 1 depicts an exemplary embodiment of an exemplary papermakingsystem. The exemplary papermaking system depicts only a part of theoverall process of making and processing paper, and may include othersteps, processes, machinery, or devices that are not shown in FIG. 1.FIG. 1 includes a drying section 12, a web spreading section 14, and acalendering section 16. It is understood that drying section 12, webspreading section 14, and calendering section 16 are exemplary only andthat these sections may include other components and processes not shownin FIG. 1.

As shown in FIG. 1, a web 18 passes through drying section 12, webspreading section 14, and calendering section 16 in a travel direction20. Web 18 may be a non-woven web, such as, for example, a paper web,non-woven polymer web, melt-blown web, or melt-spun web.

Drying section 12 receives web 18 in a moist or wet state, and dries web18 using a dryer. As generally described herein, web 18 is in arelatively drier state as it passes from drying section 12 to webspreading section 14 as compared to when web 18 entered drying section12. The degree of drying performed in drying section 12 may varydepending on the design of the papermaking system. For example, the webmay exit drying section 12 at a moisture content of less than or equalto about 30%, less than or equal to about 25%, less than or equal toabout 20%, less than or equal to about 15%, less than or equal to about10%, or less than or equal to about 5%, such as in a range from about 0%to about 25%, from about 5% to about 20%, or from about 5% to about 15%.

As shown in FIG. 1, the dryer of drying section 12 may be a Yankeedryer, such as known in the art. The elements of the Yankee dryer areonly partially shown in FIG. 1, and it is understood that drying section12 may include other components not shown in FIG. 1. The dryer mayinclude a dryer roll 22 that may be enclosed by a dryer hood or dryershroud 23. Dryer roll 22 facilitates travel of web 18 through the dryerhood 23 where web 18 is dried, such as by the application of heat.Drying section 12 may also include a pressure roll 24 that maintainstension in web 18 as it passes through drying section 12 and into webspreading section 14. According to some embodiments, drying section 12may include a blade (not shown), such as, for example, a doctoring orcreping blade, to facilitate removal of web 18 from dryer roll 22 as itpasses to pressure roll 24.

Web spreading section 14 includes an air spreader 26. Air spreader 26expels a gas towards web 18 as web 18 passes from drying section 12 tocalendering section 16. Air spreader 26 may also be referred to as a“web spreader,” and prevents, removes, or smooths wrinkles and folds inweb 18 through the application of expelled gas. According to someembodiments, air spreader 26 may be positioned downstream of dryingsection 12, such as, for example, downstream of pressure roll 24 ordownstream of a creping blade (not shown) that facilitates removal ofweb 18 from dryer roll 22. According to some embodiments, web spreader26 may be positioned upstream of a calendering section, embossingsection, calendering roll, or embossing roll. According to someembodiments, web spreader 26 may be positioned upstream of a windingroll or rewinding roll. Air spreader 26 may include a base portion 28and a plurality of nozzles 30. Nozzles 30 may project from or extendfrom base portion 28. For example, nozzles 30 may include a tubeextending or projecting from base portion 28 through which the gas isexpelled.

According to some embodiments, base portion 28 may provide a conduit forthe gas to pass to the plurality of nozzles 30, through which the gas isexpelled towards web 18. For example, the gas expelled from air spreader26 may come from a gas supply or gas source (not shown) that isoperatively coupled to base portion 28. The gas supply may include, forexample, a compressed gas supply, such as, for example, a compressed airtank. The gas from the gas supply or gas source may pass through a tubeor hollow portion of base portion 28 to supply the gas to nozzles 30.The gas may then pass to nozzles 30 where it is expelled towards web 18.The gas supply or gas source may include a compressor to increase thepressure of the gas expelled from nozzles 30. The compressor may includea variable speed compressor to adjust the pressure at which gas issupplied and expelled from air spreader 26. The gas supply or gas sourcemay be operatively connected to base portion 28 through hoses or pipinggenerally known in the art.

According to some embodiments, nozzles 30 direct the gas towards web 18to facilitate spreading of the web. According to some embodiments,nozzles 30 are positioned such that they expel the gas in a direction 34that is at least partially opposed to travel direction 20 of web 18, asshown, for example, in FIG. 1. Direction 34 may be, for example, adirection that is directed towards an edge of web 18, but also directedagainst travel direction 20.

According to some embodiments, direction 34 may be, for example, in adirection that is directed towards an edge of web 18, but also directedwith travel direction 20.

FIG. 2A shows a cross-section of a portion of exemplary air spreader 26,including a base portion 28 and nozzles 30. For example, FIG. 2A shows across-section of base portion 28, as viewed through plane A-A of FIG. 1.FIG. 2A also shows travel direction 20 and gas expulsion direction 34.Although the manufacture of air spreader 26 may take many forms, in someembodiments, such as shown in FIG. 2A, base portion 28 may include ahollow tubular component 29, such as a metallic or plastic tube formingat least part of base portion 28. The expelled gas may be received viaan inlet of tubular component 29, such as inlet 33 of FIG. 2B. Nozzles30 may be attached to the exterior of tubular component 29 of baseportion 28 and holes 31 in tubular component 29 allow the gas to flowfrom the interior of base portion 28 through nozzles 30, where the gasis expelled towards web 18. The shape and direction of nozzles 30determines the direction of the expelled gas.

Although FIG. 2A shows a single tubular component 29, base portion 28may include more than one tubular component with each tubular componentbeing connected to one or more nozzles 30. For example, base portion 28may include two tubular components with each tubular component expellinggas toward a different edge of web 18. According to some embodiments,base portion 28 may include a plurality of tubular components positionedin series in travel direction 20.

FIG. 2A shows tubular component 29 having a generally circular crosssection, but it is contemplated that tubular component 29 may have anyshape of cross section, such as, for example, an elliptical, square, orrectangular cross section.

As can be seen in FIG. 2A, direction 34 of the gas expelled from nozzles30 may be directed against travel direction 20, but offset by an angle φtowards edges 19A and 19B (shown in dashed lines in FIG. 2A) of web 18.Angle φ, which represents direction 34 projected into plane of web 18(which is parallel to plane A-A of FIG. 1), between travel direction 20and direction 34 may be greater than 0 degrees (i.e., when direction 34is directly opposite travel direction 20 in the plane of web 18), butless than 90 degrees (i.e., when direction 34 is perpendicular to traveldirection 20 in the plane of web 18). As shown in FIG. 2A, nozzles 30expel a gas at an angle φ that is partially opposed to travel direction20. Angle φ may be, for example, between 5 degrees and 80 degrees, suchas between 10 degrees and 75 degrees, between 30 degrees and 60 degrees,between 10 degrees and 30 degrees, between 30 degrees and 45 degrees,between 45 degrees and 60 degrees, or between 60 degrees and 75 degrees.The different nozzles 30 may each have the same or different angle φ.

Angle φ is measured by projecting direction 34 into the plane of web 18;however, it is understood the direction 34 will also be angled into web18 itself, such as by an angle θ (as shown in FIG. 3A) projected intothe plane of FIG. 3A (which is the same as the plane of FIG. 1 in thedrawings). For example, as shown in FIG. 3A, angle θ may be greater than0 degrees (i.e., when direction 34 is directly opposed to traveldirection 20 of web 18 when projected into the plane of FIG. 3A), butless than 90 degrees (i.e., when direction 34 is perpendicular to traveldirection 20 when projected into the plane of FIG. 3A). Angle θ may be,for example, between 15 degrees and 90 degrees, such as between 30degrees and 60 degrees or between 40 degrees and 50 degrees, between 45degrees and 60 degrees, or between 60 degrees and 90 degrees. Withoutbeing bound by a particular theory, it is believed that varying angle θmay alter the amount of sheet drag experienced by web 18 as it passesair spreader 26.

The different nozzles 30 may each have the same or different angle θ.Angle θ is determined when air spreader 26 is in a working position 46,such as described in this disclosure.

According to some embodiments, angles φ and θ may be, for example, in arange from 90 degrees and 180 degrees (such direction 34 in the samedirection as travel direction 20), such as between 120 degrees and 150degrees or between 130 degrees and 140 degrees, between 135 degrees and150 degrees, or between 150 degrees and 180 degrees. For example, whenangle φ is greater than 90 degrees, direction 34, when projected intothe plane of web 18 is toward an edge of web 18 but also partially inthe direction of travel direction 20. When angle θ is greater than 90degrees, nozzles 30 projected into the plane of FIG. 3A are at leastpartially directed into web 18 in the direction of travel direction 20.

According to some embodiments, some nozzles in the plurality of nozzles30 may be partially opposed to travel direction 20 and some nozzles inthe plurality of nozzles 30 may be partially in the direction of traveldirection 20.

Together angles φ and θ describe the angular components of direction 34in a three-dimensional papermaking system.

FIG. 2B shows a portion of exemplary air spreader 26 viewed from planeB-B of FIG. 1 together with web 18 and foil 38, with travel direction 20of web 18 being into the plane of FIG. 2B. As shown in FIG. 2B, nozzles30 may be directed in two nozzle groups 30A and 30B toward respectiveedges 19A and 19B of web 18. For example, nozzle group 30A, as shown inFIG. 2B, expels gas in a direction 34 towards edge 19A of web 18.Similarly, nozzle group 30B expels a gas in a direction 34 towards edge19B of web 18. Each of nozzle groups 30A and 30B may be directed awayfrom a center line 44, which corresponds to the center of web 18, suchas, for example, at an angle φ, but towards different edges of web 18.

As also shown in FIG. 2B, nozzles 30 may extend towards the edge ofsheet 18 such that the gas expelled in directions 34 is expelled towardsedges 19A and 19B of web 18 along the width of web 18. According to someembodiments, however, nozzles 30 may extend past edges 19A and 19B ofweb 18, such that the expelled gas from nozzles 30 at the edge of baseportion 28 do not expel a gas that contacts web 18, but the nozzles 30that are closer to the center of base portion 28 do expel a gas thecontacts and spreads web 18.

According to other embodiments, nozzles 30 may be placed in such a waythat they do not reach the edges 19A and 19B of web 18. For example,nozzles 30 may expel a gas in directions 34, but nozzles 30 arepositioned at a spacing less than the entire width of web 18.

According to some embodiments, the pressure exerted from nozzles 30across the length of air spreader 26 may be relatively uniform. It iscontemplated, however, that the pressure from different nozzles 30 maybe varied, such as through different sized or shaped nozzles, throughthe use of more than one tubular component 29, through variations inbase portion 28, or through the use of a controller. Varying thepressure at different positions of air spreader 26 may further improvethe performance of air spreader 26.

As also shown in FIG. 2B, nozzles 30 may be placed relatively close toweb 18. For example, when in the working position 46, the nozzles 30 maybe positioned in a range from about 0.25 inches and about 5 inches fromweb 18, such as from about 0.5 inches to about 5 inches, from about 1inch to about 4 inches, from about 1 inch to about 3 inches, from about1 inch to about 2 inches, from about 2 inches to about 4 inches, fromabout 2 inches to about 3 inches, from about 3 inches to about 4 inches,from about 3 inches to about 4 inches, from about 4 inches to about 5inches, or from about 0.5 inches to about 2 inches from web 18. Nozzles30 expel the gas towards a first face or side of web 18 while a secondface or side of web 18 faces foil 38. Foil 38 acts to support web 18 asthe gas from air spreader 26 blows against it. Foil 38 may prevent web18 from developing holes or wrinkles as a result of the pressure fromthe expelled gas.

By expelling a gas towards web 18, such as in direction 34, air spreader26 may prevent or remove wrinkles or folds in web 18 by spreading web18. For example, as the expelled gas presses against web 18 in direction34, it may smooth, reduce, or prevent folds or wrinkles in the web byspreading web 18 towards an exterior edge of web 18. For example, thedirection 34 and velocity of the gas may smooth wrinkles and folds inweb 18, thereby preventing visual defects such as folds and wrinkles inweb 18 as it passes through calendering section 16. According to someembodiments, air spreader 26 may prevent or remove wrinkles or folds bypushing them to the edge of web 18. According to some embodiments, airspreader 26 may also increase tension in web 18. For example, thevelocity and direction 34 of the expelled gas may increase the tensionby spreading web 18 towards an exterior edge (19A and 19B of FIG. 2B).By increasing the tension and/or preventing wrinkles in web 18, airspreader 26 may also incrementally increase the width of web 18.

Air spreader 26 may be attached to the papermaking system throughvarious means. For example, air spreader 26 may be attached to a frameor support structure (not shown) of the papermaking system. Air spreader26 may also constitute a separate component that is coupled or attachedto existing processing equipment. For example, air spreader 26 may, insome embodiments, be bolted, clamped, or otherwise fastened tostructural elements of a paper making apparatus. It is thereforecontemplated that air spreader 26 may be removable from other parts ofthe papermaking system, which may facilitate maintenance or replacementof air spreader 26.

Air spreader 26 may also act to remove dust and other particles from web18 through the application of the expelled gas. For example, sincedirection 34 is at least partially opposed to travel direction 20, theexpelled gas may lift particles or dust from web 18. This may furtherincrease the visual appeal of a final product because the dust andparticles will not become embedded in the web as it passes throughsubsequent calendering or winding sections.

According to some embodiments, air spreader 26 may optionally be movableto facilitate maintenance of air spreader 26 and to adjust the operationof air spreader 26. For example, as shown in FIG. 3A, air spreader 26may include a moveable portion 32 that allows air spreader 26 to bemoved such that the air spreader 26 is then farther away from web 18.When air spreader 26 is positioned such that the nozzles 30 are directedtowards web 18, this position may be referred to as a working position46. When air spreader 26 is moved away from web 18, this may be referredto as a resting position 48. An exemplary resting position 48, such asshown in FIG. 3A may be such that nozzles 30 are not directed towardsweb 18. For example, FIG. 1 and FIG. 3A show air spreader 26 in aworking position 46. In some embodiments, movable portion 32 may rotateair spreader 26 in a direction 36 to a resting position 48. Theexemplary resting position 48 in FIG. 3A is shown by dotted linesrepresenting air spreader 26 after it has been rotated away from web 18.

A resting position may serve one or more of several purposes. Forexample, it may facilitate cleaning of air spreader 26, such as nozzles30 and base portion 28. It may also facilitate maintenance of themachinery in air spreader 26, such as a compressor or compressed gassupply (not shown), gas supply hoses (not shown), or structuralequipment (not shown). The resting position may further facilitatecleaning and maintenance of the other components of the papermakingsystem. The resting position may also facilitate cleaning of airspreader 26, while allowing continuous processing of web 18. Forexample, by moving air spreader 26 away from web 18, technicians ormaintenance personnel can service air spreader 26 while allowing web 18to continue being processed by the papermaking system.

Although FIG. 3A shows movable portion 32 as rotating air spreader 26from a working position 46 to a resting position 48, it is understoodthat air spreader 26 may be moved between working position 46 andresting position 48 by other means. For example, movable portion 32 mayinclude a slidable frame that moves air spreader 26 away from web 18.For example, the slidable frame may allow air spreader 26 to slide intoor out of the plane of FIG. 1 or perpendicular to the travel direction20, as shown in FIG. 3B. FIG. 3B depicts a view of portions of webspreading section 14 from a plane parallel to plane A-A of FIG. 1, butviewed from a side of web 18 opposite air spreader 26. FIG. 3B shows airspreader 26 being moved from a working position 46 (dashed lines beneathweb 18) to a resting position 48 in direction 36 away from web 18, shownin solid lines. This movement is facilitated by movable portion 32 onwhich air spreader 26 may slide or roll. In this way, air spreader 26may be moved clear of web 18 to facilitate maintenance and cleaning ofair spreader 26.

In other embodiments, a slidable frame may move web spreader 26vertically or diagonally away from web 18, such as, for example, in theplane of FIG. 1, but away from web 18. According to some embodiments,movable portion 32 may operate to swing air spreader 26 clear of web 18,such as, for example, by rotating air spreader 26 about an axisperpendicular to the plane of web 18, as shown in FIG. 3C. As shown inFIGS. 3B and 3C, resting position 48 (solid lines) may lie away from web18. It is contemplated that the exemplary movable elements may also beused in combination with each other. For example, air spreader 26 may bemoved vertically or horizontally on a slidable frame and then rotatedabout rotatable portion.

As shown in FIG. 1, web spreading section 14 may optionally include afoil 38. Foil 38 may be positioned relatively close to web 18. When thegas is expelled from air spreader 26 towards web 18, web 18 may flex orbow as the gas is applied. Foil 38 supports web 18, thereby preventingweb 18 from breaking, developing holes, or tearing.

Although FIG. 1 shows only one exemplary foil 38, it is understood thatother foils or supports (not shown) may be used to support or retain web18 throughout web spreading section 14. For example, one or more foils,bars, or rollers may be placed above or below web 18 to support web 18as it passes from drying section 12 through web spreading section 14 tocalendering section 16. Additional rollers (not shown) may also affectthe path of web 18 to maintain or adjust the tension of web 18 as ittravels through web spreading section 14.

According to some embodiments, web spreading section 14 may optionallyinclude a collector 40. Collector 40 may trap or collect dust or otherparticles that are removed from web 18 by air spreader 26. Collector 40may include a negative pressure source, such as a vacuum, to attract thedust and particles to collector 40.

After passing through web spreading section 14, web 18 may pass tocalendering section 16. According to some embodiments, calenderingsection 16 may include one or more calendering rollers 42. Calenderingrollers 42 may be smooth surfaced or apply a pattern, embossment, ortexture to web 18 by applying pressure to web 18 to impart a texture orpattern to the web. According to some embodiments, calendering rollers42 may include embossing rollers that impart a textured pattern to web18 through a raised pattern on the embossing rollers that alters thesurface of web 18, as known in the art. Because calendering rollers 42and embossing rollers apply a visual pattern or texture to web 18, whenweb 18 enters the rollers with folds or wrinkles, the applied pressurecan press the fold or wrinkle into the pattern creating a visual defect.Similarly, if the fold or wrinkle is later removed or smoothed out, thevisual pattern from calendering or embossing will be broken or deformedwhere the fold or wrinkle was present. By preventing or smoothing foldsand wrinkles, air spreader 26 prevents these visual defects by providinga smoother web 18 as the web enters calendering section 16.

According to some embodiments, calendering section 16 may include one ormore winding rollers (not shown) after or in place of calenderingrollers 42. A winding roller collects web 18 by continuously rotating towrap web 18 around a winding roll for subsequent storage or transport.Similar to calendering rollers 42, air spreader 26 may prevent visualdefects from being introduced into a rolled web by using an air spreaderprior to a winding roll to smooth the wrinkles and folds as web 18passes to the winding roller.

Although FIGS. 1, 2A, and 2B show generally straight, circularcross-sectioned nozzles, it is understood that these are exemplary onlyand that other nozzle shapes could be used. FIGS. 4A-4H show otherexemplary configurations for nozzles 30. For example, FIG. 4A shows aconical nozzle that expels a cone of air towards web 18. FIG. 4B showsan elongated rectangular nozzle. FIG. 4C shows a tapered nozzle having arectangular opening through which the gas is expelled, but a tapered ortriangular shape. FIG. 4D shows a nozzle having a circular base, but arectangular opening through which the gas is expelled. FIG. 4E shows anozzle having a circular base and a rectangular opening, through whichthe gas is expelled, but a generally tapered shape. FIG. 4F shows atubular nozzle having a generally circular cross-section, but a bentportion to direct the gas in direction 34. FIG. 4G shows a bent tubesimilar to FIG. 4F, but having a generally rectangular cross-section.FIG. 4H shows a nozzle having a projected housing from base portion 28to expel a gas in direction 34. It is also contemplated that variouscombinations of the nozzles shown in FIGS. 4A-4H may also be used. Forexample, the nozzles shown in FIGS. 4F and 4G may have tapered orconical shapes, as shown in FIGS. 4A and 4C, respectively. Othercombinations of nozzle shapes are also contemplated. However, othernozzle shapes may be used as part of the air spreader, and would beknown to those of skill in the art. Direction 34 and angles φ and θ aremeasured with respect to the central axis of nozzle 30, as shown inFIGS. 4A-4H.

Base portion 28 may also have a variety of cross-sectional shapes.Although FIGS. 1, 2A, 2B, and 3A depict a roughly circular tube for baseportion 28, it is contemplated that square, rectangular, or ellipticalcross-sections may also be used. However, the use of a regular geometriccross-section, such as a circular, square, or rectangular cross-section,for base portion 28 may facilitate easier manufacture of air spreader26.

The components of air spreader 26 may be made from any suitablematerials appropriate for the environment in which it is used. Forexample, base portion 28 and nozzles 30 may be made from aluminum,stainless steel, copper, or other metals or alloys. They may also bemade from plastic or composite materials, such as, for example, PVC,ABS, or polymer composites. It is also contemplated that the componentsof air spreader 26 may be made from different materials. For example,base portion 28 and nozzles 30 may be made from metallic materials orplastics, but a hose or tube supplying the gas to air spreader 26 may bemade from, for example, steel flex hose, plastic tubing, or rubbertubing. Other combinations or materials are also contemplated and anysuitable combination may be used.

Although FIG. 1 shows a single air spreader 26, it is contemplated thatmore than one air spreader 26 may be present. For example, two or moreair spreaders may be placed sequentially along travel direction 20 inweb spreading section 14. According to some embodiments, more than oneair spreader 26 may be placed in parallel across the width of web 18.For example, nozzle group 30A may include a first air spreader andnozzle group 30B may include a second air spreader. According to someembodiments, one or more air spreaders 26 may be placed in web spreadingsection 14, prior to, for example, calendering rollers 42, and one ormore additional air spreaders 26 may be placed along travel direction 20after calendering rollers 42 and prior to, for example, a winding roll(not shown). Other combinations of two or more air spreaders is alsopossible.

It is contemplated that any number of nozzles 30 may be used tofacilitate spreading of web 18. Different nozzles in air spreader 26 mayhave different shapes.

It is also contemplated that air spreader 26 may have more than one rowof nozzles 30, such as, for example, two or more rows of nozzles 30.When more than one row of nozzles 30 is present, the rows may includethe same number of nozzles 30 or may include different numbers ofnozzles 30.

According to some embodiments, the papermaking system or web spreadingsection 14 may include a control unit (not shown) to control theoperation of air spreader 26. For example, the control unit may includea computer processor and/or memory having instructions or softwareprogrammed to control the operation of air spreader 26.

According to some embodiments, the control unit may operate to controlthe movement of air spreader 26, for example, from a working position 46to a resting position 48. For example, at a break in web 18, or when thepapermaking system is not in operation, the control unit may move airspreader 26 from a working position 46 to a resting position 48. Thismay facilitate maintenance or cleaning of both web spreader 26 and thepapermaking system. The control unit may also be configured to controlthe flow of the gas expelled from air spreader 26. For example, when airspreader 26 is in a working position 46, the control unit may control anair compressor or pump to pressurize the air spreader such that the gasis expelled from nozzles 30 towards web 18. When air spreader 26 is in aresting position 48, the control unit may depressurize air spreader 26,such that the gas is not expelled from nozzles 30.

According to some embodiments, the control unit may also operate topressurize or depressurize air spreader 26 depending on whether web 18is present and the papermaking system is operation. For example, if web18 is not present, the control unit may depressurize air spreader 26until web 18 begins to pass through web spreading section 14, at whichtime, the control unit pressurizes air spreader 26.

It should be noted that the methods and systems described herein shouldnot be limited to the examples provided. Rather, the examples are onlyrepresentative in nature.

In addition, other embodiments will be apparent from consideration ofthe specification and practice of the present disclosure. It is intendedthat the specification and examples be considered as exemplary only,with a true scope and spirit of the invention being indicated by thefollowing claims.

1.-12. (canceled)
 13. A method for reducing wrinkles in a paper webduring papermaking, the method comprising: drying a continuous paper webhaving a travel direction using a dryer; providing a foil along aportion of a first side of the dried paper web; expelling a gas toward asecond side of the dried paper web via an air spreader, the air spreadercomprising a plurality of nozzles oriented in a direction at leastpartially opposed to the travel direction of the dried paper web; andsubsequently contacting the dried paper web with at least one roll. 14.The method of claim 13, wherein the at least one roll is a calendaringroll.
 15. The method of claim 13, wherein the at least one roll is awinding roll.
 16. The method of claim 13, further comprising positioningthe air spreader using a moveable positioning component.
 17. The methodof claim 13, further comprising rotating the air spreader between aresting position and a working position, wherein the working position iscloser to the dried paper web than the resting position.
 18. The methodof claim 17, further comprising pressurizing the air spreader when theair spreader in the working position, and depressurizing the airspreader when the air spreader is in the resting position.
 19. Themethod of claim 13, wherein expelling gas toward the dried paper webcomprises expelling the gas at a direction and velocity sufficient toreduce wrinkles in the dried paper web.
 20. The method of claim 13,wherein expelling gas toward the dried paper web comprises expelling gasat a direction and velocity sufficient to increase tension within thedried paper web.
 21. The method of claim 13, wherein each nozzle in theplurality of nozzles comprises a metal tube extending from a baseportion of the air spreader.
 22. The method of claim 13, wherein eachnozzle in the plurality of nozzles expels a cone-shaped stream of gas.23. A system for stabilizing a web, comprising: a web having a traveldirection, the web having a first side and a second side; a foildisposed along a portion of the first side of the web; an air spreaderlocated in proximity to the second side of the web, the air spreadercomprising a plurality of nozzles configured to expel a gas toward thesecond side of the web in a direction at least partially opposed to thetravel direction.
 24. The system of claim 23, further comprising a dryerlocated upstream of the air spreader and configured to dry the web. 25.The system of claim 23, further comprising at least one calendering rolldownstream of the air spreader.
 26. The system of claim 23, furthercomprising at least one winding roll downstream of the air spreader. 27.The system of claim 23, wherein the air spreader is attached to apositioning component configured to change a position of the airspreader.
 28. The system of claim 27, wherein the positioning componentis rotatable such that the air spreader can be moved between a restingposition and a working position, the working position being closer tothe web than the resting position.
 29. The system of claim 28, furthercomprising a control unit configured to pressurize the air spreader whenthe air spreader is in the working position, and to depressurize the airspreader when the air spreader is in the resting position.
 30. Thesystem of claim 23, wherein the air spreader is configured to expel thegas toward the second side of the web at a direction and a velocitysufficient to reduce wrinkles from the web.
 31. The system of claim 23,wherein the air spreader is configured to expel the gas toward thesecond side of the web at a direction and a velocity sufficient toincrease tension within the web.
 32. The system of claim 23, whereineach nozzle in the plurality of nozzles comprises a metal tube extendingfrom a base portion of the air spreader.
 33. The system of claim 23,wherein each nozzle in the plurality of nozzles is configured to expel acone-shaped stream of gas.